Patients suffering from serious medical emergencies as well as traumatic injuries such as facial or chest trauma frequently cannot breathe because their airway is blocked by blood, gastric contents, and other matter. They may be barely conscious or not conscious at all. Time is very limited for the emergency personnel on the scene, as oxygen deficiency in the blood begins almost as soon as breathing stops, and permanent damage to the brain will take place after three minutes.
Standard emergency practice for such patients heretofore has been to insert a laryngoscope, a lighted probe, into the mouth to push the tongue aside and search for the vocal cords as the insertion site or target for a plastic or other tube which can serve as an airway. The search is assisted by a suction probe which the user manipulates to remove the blocking materials. As soon as the vocal cords are seen, the attending emergency person inserts the relatively simple airway tube into the trachea between the vocal cords; the tube's outside end is typically connected to a positive pressure oxygen device. The airway tube usually is equipped with and passes through a balloon which seals the airway to prevent aspiration into the lungs of gastric contents and/or blood, which may continue to flow into and fill the throat area well after the airway passage is secured.
The laryngoscopic procedure is frequently performed under quite stressful conditions. Copious amounts of fluid flowing into the oropharynx is very common and frequently frustrates the efforts of emergency personnel to administer oral intubation. It is recommended that the most experienced person on the scene perform the procedure, which often must take place while the patient is undergoing other emergency treatment as well. Confusion and well-meant gestures from others often make it difficult for the person attempting the oral intubation to retain control of the process. A major cause of the difficulty of the procedure is that the laryngoscope is held in the left hand, while the right hand is occupied in manipulating the suction tube. As soon as a clear passage to the vocal cords is established, the suction tube must be removed and the airway tube picked up and moved to its place, i.e. inserted between the vocal cords, by the right hand, while the left hand still holds the tongue aside with the laryngoscope. During this maneuver, the blood and gastric matter commonly continues to flow into the airway, and the vocal cords disappear from view before the airway tube can be inserted. Delay is caused not just by the act of discarding the suction tube and picking up the airway tube, but also by the user having to glance away from the vital spot where the airway tube must be placed. Frequently when an opportunity is missed, further time is lost because it is determined that the patient must be ventilated with oxygen. The risk of aspiration of fluids into the lungs is extremely high at this point.
Standard and widely used laryngoscopes and suction tubes have not alleviated the problems described above; in fact, they exacerbate them in that the three articles handled by the user--the laryngoscope, the suction tube, and the airway tube--are completely separate and each requires the separate attention of the user.
Rosoff, in U.S. Pat. No. 5,183,031, combines a fiber optic light with a small suction channel, but does not provide for a blade, which is necessary to move the tongue away from the obstructed area.
Bartlett, in U.S. Pat. NO. 4,947,896, integrates the suction tube with the blade of the laryngoscope, i.e. it is entrained preferably in a service tube in the blade (col. 6, lines 4-6). This elaborate design is difficult to make and, because of the integration of the tube and the blade, means that the suction tube cannot economically be disposed of after use but must be sterilized along with the blade. Bartlett says the same tube can be used for either suction or "introduction of materials". He uses a channel alongside of the handle for guiding the tube (col. 6 line 45). Bartlett's main contribution to the art appears to be the "gull wing" shape of his blade.
A more or less standard appearance of a laryngoscope blade and handle assembly is shown in Greenblatt's U.S. Pat. No. Des 271,135. The present invention may be used with such a laryngoscope.
Slater, in U.S. Pat. No. 4,878,486, discloses a disposable sheath, sleeve or pocket-like device for covering the blade of a laryngoscope, and utilizes a ready source of vacuum to assure a tight fit of the sheath to the blade.
Suction is drawn directly through the blade and handle of a laryngoscope designed specifically for laser treatment of the larynx, in U.S. Pat. No,. 4,832,004 by Heckele et al. The passage is designed to remove gaseous materials rather than liquids.
None of the above devices satisfy the need for a convenient, easily manipulable way or device to clear the airway and insert an oxygen tube.